喀斯特典型地物混合光谱与复合覆盖度关系研究  

Study on the Relation between Fraction Cover and Mixed Spectra in Karst Enviroment

作　　者：刘波[1] 岳跃民[2,5] 李儒[3] 王克林[4] 张兵[4] 童庆禧[1] 

机构地区：[1]中国科学院遥感应用研究所遥感科学国家重点实验室,北京100101 [2]中国科学院亚热带农业生态研究所,湖南长沙410125 [3]香港中文大学太空与地球信息科学研究所,中国香港 [4]中国科学院对地观测与数字地球科学中心,北京100080 [5]中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《光谱学与光谱分析》2010年第9期2470-2474,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(40971205);国家重点基础研究发展计划(973计划)项目(2006CB403208);中国科学院重大科研装备研制项目(地面成像光谱仪研制);遥感科学国家重点实验室科研支持基金项目(03000300649)资助

摘　　要：喀斯特石漠化是我国西南喀斯特地区面临的主要生态环境问题之一。岩石裸露率以及植被覆盖度是石漠化主要的地面表现特征,也是评价石漠化的关键指标。由于喀斯特地区复杂的地貌情况,使得评价石漠化需要多种地物类型覆盖度信息。该文在实测光谱支持下,构建了系列光谱指数,初步分析了喀斯特地区典型地物混合光谱与复合覆盖度的关系。结果表明,光谱指数与覆盖度的相关性远远高于光谱反射率与覆盖度的相关性。植被指数和绿色植物(photosynthetic vegetation,PV)覆盖度有着很好的线性关系;该文构造的光谱指数和干枯植被覆盖度(non-photosynthetic vegetation,NPV)、土壤覆盖度有着较好的相关性,可决系数分别达0.70和0.73,显示了有估算NPV和土壤覆盖度的潜在能力。而光谱指数和裸岩率的相关系数稍低,最高达0.55,可以提供一定的裸岩率信息。所构建的4种指数形式中,表征光谱吸收特征深度的指数形式和NPV、土壤覆盖度以及裸岩率均拥有最高的相关性。这为高光谱遥感在喀斯特石漠化信息提取的应用进行了初步的探索。Karst rocky desertification is one of the most serious eco-environmental problems of land degradation in karst regions,Southwest China.The fractional cover of vegetation and exposed bedrock are the main land surface symptoms and essential assessing indicators of karst rocky desertification.To assess the extent of rocky desertification in complex karst environments,the information of multiple land cover types fraction is needed.Based on in situ spectral reflectance data,this study proposed several spectral indices and explored the relationship between spectral features of main land cover types and their responding fractional cover.The results showed that spectral indices have much higher correlation coefficients with fractional cover than does spectral reflectance.Vegetation indices have good linear relation with fractional cover of photosynthetic vegetation（PV）.The proposed spectral indices have high correlation coefficients with fractional cover of non-photosynthetic vegetation（NPV） and bare soil,with R2 0.70 and 0.73,respectively.Lower correlation coefficients（R2=0.55） with the factional cover of exposed bedrock,were observed.The absorption depth of four forms of the proposed indices has the highest correlation coefficient with the fractional cover of NPV,bare soil,and exposed rock.This study indicates that hyperspectral remote sensing has the potential for the extraction of karst rocky desertification information.

关 键 词：光谱分析 喀斯特 覆盖度 石漠化 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]